Understanding the Mechanisms of Hypervelocity Impact Induced Failures on Space Solar Arrays

Besides being one of the most critical satellite components directly linked to mission success, solar arrays are the component most exposed to the orbit environment. The evolution of space solar arrays to higher power and voltage ranges involved several failures induced by environmental effects. It was discovered that an electrostatic discharge on a high-voltage solar array, pre-charged in the space plasma environment, can be sustained by the array itself, thus resulting in permanent short circuiting of sections. Another environmental effect to be considered in this context is the hypervelocity impact (HVI) of micrometeoroids and space debris. Sources of HVI induced failures are the mechanical damage leaving behind perforations and craters, and the formation of free charges at the impact location. There is evidence that this impact plasma may trigger arcing events and, thus, poses a more significant risk to solar arrays than the current regard given to HVI effects. This paper provides an overview of solar array failure effects attributed to the hypervelocity impact of micrometeoroids. Related aspects, including solar array anomalies and HVI peculiarities, are presented along with the approach of an ESA study, the objective of which is to experimentally investigate the HVI susceptibility of modern space solar arrays.